Electric furnace for processing glass

ABSTRACT

An electric glass hot shop system is described herein that has at least one electrically powered heating unit (e.g., electric furnace, electric glory hole, electric pipe warmer, electric color box, electric annealer, electric crucible kiln) used in the processing of glass.

CLAIMING BENEFIT OF PRIOR FILED U.S. APPLICATION

This is a divisional of U.S. patent application Ser. No. 12/603,167 entitled “Electric Glass Hot Shop System” filed on Oct. 21, 2009, now U.S. Pat. No. 8,891,582, the content of which is relied upon and incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to an electric glass hot shop system that has at least one electrically powered heating unit (e.g., electric furnace, electric glory hole, electric pipe warmer, electric color box, electric annealer, electric crucible kiln) used in the processing of glass.

BACKGROUND

Extremely high temperatures are required to enable the melting, processing and forming of glass. In typical glass forming operations this high temperature requirement extends to the initial melting of the glass in a furnace, the periodic re-heating of the glass in a glory hole, the heating of the glass while applying colored additives in a color box, the pre-heating of a glass manipulating pipe in a pipe warmer, and the annealing of formed glass in an annealer. Generally, glass working equipment uses natural gas or propane fueled flames as heat sources to melt, process and form the glass. However, there are some situations or venues where a gas source is not readily available, or where the use of a gas source is excluded for safety reasons. For instance, one such situation or venue where a gas source is prohibited for safety reasons is on a cruise ship where it would be desirable to be able to perform hot glass forming shows for people vacationing on the cruise ship.

In these situations or venues, electrically heated glass working equipment are alternatives to the glass working equipment that use a gas source. The electrically heated glass working equipment utilize electrically resistive heating elements such as, for example, molybdenum disilicide to generate radiative heat. Unfortunately, electricity is typically a poor means of supplying bulk energy to glass working equipment. For instance, a typical glass furnace of about 150 lbs capacity would have to be supplied with a 400,000 BTU burner, which is the equivalent of approximately 115 KW of electrical power. However, 115 KW power supplies are generally much too expensive and bulky to be considered as a useful source of energy for such a small glass furnace. In contrast, power supplies of <35 KW are economically feasible and can be a useful source of energy for a glass furnace if a more efficient insulation package is provided and the glass is allowed a longer period of time to melt and fine out. There are several types of electrically heated glass furnaces currently available today on the market, which use low energy inputs, but they have their own problems and they often introduce design features that limit their usefulness. These problems and other problems associated with other types of glass working equipment are discussed below.

Furnace

-   -   Existing door systems have tracks and wheels which fail to         create a tight seal and are prone to energy leakage.         Furthermore, existing rear hinge designs eliminate easy access         to heating elements in the top of the furnace     -   The heating elements are mounted in the top (crown) of the         furnace, which means that the heating elements and corresponding         electrical supplies must be removed to be able to access and         service the crucible.

Glory Hole (GH)

-   -   Existing door systems are difficult to maintain and have         undesirable energy leakage.     -   There are few electric glory hole's commercially available.         Perhaps one reason for this is that heating elements are located         in a position that creates a potential for contact with glass         which if this occurred it would render the heating elements         useless. Another possible reason is that electric heat elements         provide mostly radiant heat with very little convection energy         like gas fired glory holes and as a result there would be         undesirable hot spots in the walls next to the heating element         holders.

Combination Pipe Warmer and Color Box

-   -   There are no electrically heated pipe warmers commercially         available.

Annealer

-   -   Existing annealer door seals fail due to their exposure to heat         and abrasion during the loading and unloading of the annealer.

Annealer's Crucible Kiln

-   -   Existing door is too large and when it is opened to much heat         escapes.

Thus, any enhancement of the traditional glass working equipment and in particular the electrical glass working equipment would help improve the melting, processing and forming of glass.

SUMMARY

In one aspect, the present invention provides an electric glass hot shop system for processing glass that includes: (a) an electric furnace; (b) an electric glory hole; (c) an electric pipe warmer; (d) an electric color box; (e) an electric annealer; and (f) an electric crucible kiln. The electric glass hot shop system is well suited to be used in a venue or situation where a gas source is prohibited to be used for safety reasons like on a cruise ship.

In another aspect, the present invention provides an electric glory hole for processing glass. In one example, the electric glory hole includes: (a) a body with a first opening located therein; and (b) a door system including a first door which is hung over the first opening in the body, where the first door has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block. The door system may further include: (a) a second door which has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block; (b) a third door which has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block; and (c) the first door is hung over the first opening on the body, and the second door is hung on the first door, and the third door is hung on the second door. The electric glory hole may also include a specially designed refractory element baffle which is located within the body, where each refractory element baffle includes a block with a passage through which an heating element is inserted and a cavity in which hangs the heating element, where the cavity is larger than the heating element, and where the cavity is sized to encompass at least three sides of the heating element. Furthermore, the electric glory hole may have one or more specially designed insulation packages which help to maintain a desired temperature within the body.

In yet another aspect, the present invention provides an electric furnace for processing glass. In one example, the electric furnace includes: (a) a crucible unit; and (b) a heating unit, coupled to the crucible unit, where the heating unit has an opening formed therein and a door attached to a cantilevered arm which has a hinge connected to at least an outer portion of the heating unit, where the cantilevered arm rotates on the hinge such that the door is moved to cover the opening and prevent access to an interior of the heating unit and the crucible or the door is moved away from the opening to allow access to the interior of the heating unit and the crucible. The heating unit may further include a crown suspension system located therein which supports at least one heating element, where the crown suspension system includes a ring of locking bricks that support a crown casting which then supports the at least one heating element. Furthermore, the electric furnace may have one or more specially designed insulation packages which help to maintain a desired temperature within the crucible and the heating unit.

Additional aspects of the invention will be set forth, in part, in the detailed description, figures and any claims which follow, and in part will be derived from the detailed description, or can be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram of an exemplary electric glass hot shop system which includes an electric furnace, an electric glory hole, an electric pipe warmer, an electric color box, an electric annealer, and an electric crucible kiln in accordance with an embodiment of the present invention;

FIGS. 2A-2G are different diagrams illustrating in greater detail the exemplary electric furnace shown in FIG. 1 in accordance with an embodiment of the present invention;

FIGS. 3A-3M are different diagrams illustrating in greater detail the exemplary electric glory hole shown in FIG. 1 in accordance with an embodiment of the present invention;

FIGS. 4A-4B are different diagrams illustrating in greater detail the exemplary electric pipe warmer and the exemplary electric color box shown in FIG. 1 in accordance with an embodiment of the present invention;

FIGS. 5A-5G are different diagrams illustrating in greater detail the exemplary electric annealer shown in FIG. 1 in accordance with an embodiment of the present invention; and

FIGS. 6A-6D are different diagrams illustrating in greater detail the exemplary electric crucible kiln shown in FIG. 1 in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, there is shown a block diagram of an exemplary electric glass hot shop system 100 in accordance with an embodiment of the present invention. In this example, the electric glass hot shop system 100 includes an electric furnace 102, an electric glory hole 104, an electric pipe warmer 106, an electric color box 108, an electric annealer 110, and an electric crucible kiln 112. The electric glass hot shop system 100 further includes a power supply 114 (e.g., ≤35 KW power supply 114) that supplies electricity to the electric furnace 102, the electric glory hole 104, the electric pipe warmer 106, the electric color box 108, the electric annealer 110, and the electric crucible kiln 112. Typically, the electric furnace 102 is used to melt batch materials to form a molten glass. The electric glory hole 104 is used to periodically re-heat the molten glass while a pipe is used to hold and manipulate the molten glass to form the desired glass shape. The electric pipe warmer 106 is used to pre-heat the pipe. The electric color box 108 is used to apply colored additives to the molten glass during the forming process. The electric annealer 110 is used to anneal the formed glass. The electric crucible kiln 112 which is placed under the electric annealer 110 is used to melt small quantities of glass and colored fits, usually less then 50 lbs. Each piece of electric glass working equipment 102, 104, 106, 108, 110 and 112 is considered to be an individual component that can stand and function alone rather than having to be part of the entire electric glass hot shop system 100. Each electric glass working equipment 102, 104, 106, 108, 110 and 112 is discussed and described in greater detail below with respect to FIGS. 2-6.

Referring to FIGS. 2A-2G, there are different diagrams illustrating in greater detail the exemplary electric furnace 102 in accordance with an embodiment of the present invention. The electric furnace 102 includes a crucible unit 202, a heating unit 204, and an electrical control box 206 (see FIGS. 2A-2B). The crucible unit 202 is where the batch materials are placed and then melted to form the molten glass (not shown). The crucible unit 202 is attached to the heating unit 204 in a manner that makes it easy to drop and move the crucible unit 202 out of the way when one needs to perform maintenance on the heating unit 204. Also, the crucible unit 202 can be easily dropped and removed from the heating unit 204 so a new crucible unit 202 can be quickly connected to the heating unit 204. The electrical control box 206 supplies the required electricity to one or more heating elements 208 which are located within the heating unit 204. The electric furnace 102 includes other components but only the components like a crown suspension system 210, a torsion-box door system 212, and specially designed insulation packages 214 a, 214 b and 214 c which are relevant to the present discussion are described in detail below.

As shown in FIG. 2B, the heating unit 204 incorporates the crown suspension system 210 which has a crown 216 that supports the heating elements 208 in a manner that allows the crucible unit 202 to be serviced without having to remove the crucible unit 202 from the heating unit 204. The crown suspension system 210 includes a cast tube 218 (outer body of furnace 102) which has a rabbit 220 on the bottom edge thereof is configured to receive a ring of locking bricks 222. The locking bricks 222 are arranged between the cast tube 218 and a crown casting 224. The locking bricks 222 prevent the crown 216 (which is supported by the crown casting 224) from falling down and also transfer the weight of the crown casting 224 to a lower outside ring 226 on the heating unit 204. The ring of locking bricks 222 is suspended and cantilevered in a way that leaves a clear space under the crown 216 to provide access to the crucible unit 102. The crown suspension system 210 greatly reduces the amount of down time required to change the crucible unit 102 and eliminates need for removing electrical components during service.

As shown in FIGS. 2A-2D, the heating unit 204 includes the torsion box door system 212 which has a door 228 attached to a cantilevered arm 230 in a manner that allows the door 228 to be adjusted in-and-out, up-and-down, as well as sideways. The cantilevered arm 230 has a hinge 232 which is connected to a body 234 of the heating unit 204. The cantilevered arm 230 rotates on the hinge 232 over a central axis to allow the door 228 to be moved to cover an opening in the heating unit 204 or to allow the door 228 to be moved away from the opening in the heating unit 204. The door system 212 makes it easy to change the crucible unit 202 and allow unobstructed access to the heating elements 208. The door system 212 is a marked-improvement over the traditional door systems that utilize tracks and wheels which fail to create a tight seal and are prone to energy leakage. Plus, the door system 212 is a marked-improvement over the traditional rear-hinge door systems which prevent easy access to the heating elements 208 located in the top of the furnace unit 204.

As shown in FIGS. 2B and 2E-2G, the crucible unit 202 and the heating element 204 incorporate specially designed insulation packages 214 a, 214 b and 214 c that help to prevent the interior of the electric furnace 102 from becoming too cold or too hot during the melting operation. In this example, the electric furnace 102 would normally have an internal operating temperature in a range of about 1120° C. to 1250° C. In FIG. 2E, the crucible unit 202 is shown to have a furnace crucible floor 236 which is made from an outer panel 238 and a specially designed insulation package 214 a. In this example, the specially designed insulation package 214 a includes a microporus panel 240 (approximately 1″ thick) located next to the outer panel 238, a fire brick 242 (approximately 2½″ thick) located next to the microporus panel 240, a low cement castable layer 244 (e.g., 1½″ thick intracast MZ 244) located next to the fire brick 242, and a crucible material 246 (e.g., 1½″ thick cast mullite 246) located next to the low cement castable layer 244. The crucible material 246 has an outer face 248 which is exposed to the heat.

In FIG. 2F, the crucible unit 202 is shown to have a furnace crucible wall 250 which is made from an outer panel 252 and a specially designed insulation package 214 b. In this example, the specially designed insulation package 214 b includes a microporus panel 254 (approximately ½″ thick) located next to the outer panel 252, a ceramic fiber layer 256 (e.g., 1½″ thick HP fiber frax 256) located next to the microporus panel 254, a fire brick 258 (approximately 2½″ thick) located next the ceramic fiber layer 256, a low cement castable layer 260 (e.g., 2″ thick intracast MZ 260) located next to the fire brick 258, and a crucible material 262 (e.g., 2″ thick cast mullite 262) located next to the low cement castable layer 260. The crucible material 262 has an outer face 264 which is exposed to the heat.

In FIG. 2G, the heating unit 204 is shown to have a furnace crown wall 266 which is made from an outer panel 268 and a specially designed insulation package 214 c. In this example, the specially designed insulation package 214 c includes a microporus panel 270 (approximately ½″ thick) located next to the outer panel 268, a ceramic fiber layer 272 (e.g., 3″ thick HP fiber frax 272) located next to the microporus panel 270, and a low cement castable layer 274 (e.g., 2½″ thick intracast MZ 274) located next to the ceramic fiber layer 272. The low cement castable layer 274 has an outer face 276 which is exposed to the heat.

Referring to FIGS. 3A-3M, there are several different diagrams illustrating in greater detail the exemplary electric glory hole 104 in accordance with an embodiment of the present invention. The electric glory hole 104 is mounted on a structure 301 and includes a body 302 with an opening 304 through which a pipe holding molten glass can be inserted and then manipulated to form the desired glass shape (see FIGS. 3A-3D). The electric glory hole 104 includes an electrical control box 306 which supplies the required electricity to one or more heating elements 308 (see FIGS. 3A-3D). The electric glory hole 104 includes other components but only the components like a specially designed door system 310, specially designed refractory element baffles 312, a video camera 314 and specially designed insulation packages 316 a, 316 b and 316 c which are relevant to the present discussion are described in detail below.

As shown in FIGS. 3A-3F, the electric glory hole 104 includes the specially designed door system 310 which has three doors 318, 320 and 322 where the first door 318 is hung upon the body 302 and at least partially covers the opening 304, the second door 320 is hung upon the first door 318, and the third door 322 is hung upon the second door 320. The first door 318 is larger than the second door 320 which in turn is larger than the third door 322. In this example, the first door 318 has a first hinged side 324 a and a second hinged side 324 b, where the first hinged side 324 a has a first frame 326 a that receives and supports one or more cast blocks 328 a and 328 a′ (two shown) and the second hinged side 324 b has a second frame 326 b that receives and supports one or more cast blocks 328 b and 328 b′ (two shown)(see FIGS. 3E-3F). The second door 320 has a first hinged side 330 a and a second hinged side 330 b, where the first hinged side 330 a has a first frame 332 a that receives and supports one or more cast blocks 334 a and 334 a′ (two shown) and the second hinged side 330 b has a second frame 332 b that receives and supports one or more cast blocks 334 b and 334 b′. Likewise, the third door 322 has a first hinged side 336 a and a second hinged side 336 b, where the first hinged side 336 a has a first frame 338 a that receives and supports one or more cast blocks 340 a and 340 a′ (two shown) and the second hinged side 336 b has a second frame 338 b that receives and supports one or more cast blocks 340 b and 340 b′.

The doors 318, 320 and 322 can be easily kept in optimal condition and thus allow minimal energy loss since if any of the cast blocks 328 a, 328 a′, 328 b, 328 b′, 334 a, 334 a′, 334 b, 334 b′, 340 a, 340 a′, 340 b and 340 b′ have to be replaced then all one needs to do is remove the damaged cast block from the frame 324 a, 324 b, 332 a, 332 b, 338 a and 338 b and insert the new cast block. For instance, if the first door 318 had a damaged cast block 328 a′ then one would remove pins 342 a and 342 b from the first frame 326 a and slide-out the damaged cast block 328 a′ (see FIGS. 3E and 3F). Then, the new cast block 328 a′ can be placed in the first frame 326 a and the pins 342 a and 342 b re-inserted to hold the new cast block 328 a′.

As shown in FIGS. 3B-3C and 3G, the electric glory hole 104 has a core 344 which is sized and configured to enable a pipe holding molten glass to be inserted therein through the opening 304. The core 344 is formed from interconnected fire bricks 346 and a series of refractory element baffles 312. In FIG. 3H, there is shown a perspective view of exemplary refractory element baffle 312 that includes a block 350 which has a passage 352 located in a top thereof and a cavity 354 formed in a side thereof. The passage 352 is sized to receive a heating element 308 (e.g., molybdenum discilicide heating element 308) which is inserted at least partially there through and the cavity 354 is sized to encompass and protect at least three sides of the heating element 308 (see FIGS. 3B-3C). In particular, the refractory element baffle 312 has sides 358 which protect the heating element 308 located and hanging within the cavity 354 such that when the pipe is inserted within the core 344 it will not be able to touch and damage the heating element 308. Plus, the refractory element baffle 312 with the specially shaped cavity 354 creates a high temperature shell around the heating element 308 that reflects energy into the core 344. In one embodiment, the refractory element baffle 312 is cast from a 3000° F. dense refractory and the cavity 354 where the heating element 308 hangs is approximately ½″ larger than the heating element 308. Plus, the heating element 308 when installed is recessed about 1 inch from the inner edges of the cavity 354. The refractory element baffle 312 solves the problem of having the heating element 308 to close to the pipe and helps to reduce the potential damage to the heating element 308 as well as reduce the potential hazard due to an electric shock and short circuit.

As shown in FIGS. 3B-3C and 3I-3J, the electric glory hole 104 has a video camera 314 attached thereto so that it is isolated from the heat inside the core 344. The video camera 314 is used to demonstrate what takes place inside the core 344 when the molten glass is re-heated on the pipe. In this example, the video camera 314 connects to one side 367 of a lens holder 362 which has another side 369 attached to a camera casting 360 (see FIGS. 3I and 3J). The camera casting 360 is a cast refractory block that is located within an opening 364 in the body 302. The camera casting 360 has a tapered opening 366 in communication with the core 344, where the tapered opening 366 is sized to allow adequate visual inspection of the glory hole interior from behind the back wall of the body 302. The lens holder 362 includes a heat block seal 368 that has a groove 370 which holds a lens 372 (e.g., 2″×2″ high temperature quartz lens 372) followed by an air purge gap 374 (which is supplied gas from a gas purge system 376) which is followed by another groove 378 within which is placed a glass filter lens 380. The quartz lens 372 (located next to the video camera 314) prevents hot corrosive gases located inside the core 344 from attacking the video camera 314. The glass filter lens 380 (located next to the camera casting 360) shields the video camera 314 from heat transferred from the lens 372. In one example, the video camera 358 would be mounted within 1″ of the glass filter lens 380.

As shown in FIGS. 3B-3C and 3K-3M, the electric glory hole 104 incorporates specially designed insulation packages 316 a, 316 b and 316 c that help limit the temperature of the outer shell 382 to be less than 225° F. In FIG. 3K, the electric glory hole 102 is shown to have a glory hole element block wall 383 which is made from an outer panel 384 and a specially designed insulation package 316 a. In this example, the specially designed insulation package 316 a includes a microporus panel 385 (approximately 1″ thick) located next to the outer panel 384, a ceramic fiber layer 386 (e.g., 2″ thick HP fiber frax 386) located next to the microporus panel 385, a low cement castable layer 387 (e.g., 2″ thick intracast MZ 387) located next to the ceramic fiber layer 386. The low cement castable layer 387 has an outer face 388 which is exposed to the heat.

In FIG. 3L, electric glory hole 102 is shown to have a glory hole wall 389 which is made from an outer panel 390 and a specially designed insulation package 316 b. In this example, the specially designed insulation package 316 b includes a microporus panel 391 (approximately ½″ thick) located next to the outer panel 390, a ceramic fiber layer 392 (e.g., 1½″ thick HP fiber frax 392) located next to the microporus panel 391, a fire brick 393 (approximately 2½″ thick) located next the ceramic fiber layer 392. The fire brick 393 has an outer face 394 which is exposed to the heat.

In FIG. 3M, electric glory hole 102 is shown to have a glory hole back wall 395 which is made from an outer panel 396 and a specially designed insulation package 316 c. In this example, the specially designed insulation package 316 c includes a microporus panel 397 (approximately ½″ thick) located next to the outer panel 396, a ceramic fiber layer 398 (e.g., 2½″ thick HP fiber frax 398) located next to the microporus panel 397, a fire brick 399 (approximately 2½″ thick) located next the ceramic fiber layer 398. The fire brick 399 has an outer face 381 which is exposed to the heat.

Referring to FIGS. 4A-4B, there are several diagrams illustrating in greater detail the exemplary electric pipe warmer 106 and the exemplary electric color box 108 in accordance with an embodiment of the present invention. The electric pipe warmer 106 is used to pre-heat the pipe which is used to hold and manipulate the molten glass during the forming process. The electric color box 108 is used to apply colored additives to the molten glass during the forming process. In this example, the electric pipe warmer 106 and the electric color box 108 are both mounted on the same support unit 402 and are both supplied electricity from one electrical control box 404. The electric pipe warmer 106 includes a body 406 with a pipe opening 408 formed therein and one or more heating elements 410 located therein. The pipe opening 408 is sized and positioned such that when a pipe is inserted therein the pipe will not be able to contact the heating elements 410. In this example, the pipe opening 408 is located near the bottom of the body 406 and the heating elements 410 are attached to the roof of the body 406. The heating elements 410 are attached to the roof because glass sheds that fall off the pipe during the heating process would damage the heating elements 410 if they where located near the bottom or sides of the body 406. The heating elements 410 can be nichrome elements which run through protective quartz tubes 412. The nichrome heating elements 410 can radiate at 2000° F. The electric pipe warmer 106 also includes a specially designed insulation package 414 which includes fire bricks 416 (e.g., 2300° F. fire bricks 416) which are coated with a high emissivity coating 418 that is exposed to the heat and helps to increase the heat transfer into cold pipes. The fire bricks 416 are located next to a ceramic fiber 420 (e.g., 1″ thick ceramic fiber 420) which is coating the internal portion of the body 406.

Referring to FIGS. 5A-5G, there are several diagrams illustrating in greater detail the exemplary electric annealer 110 in accordance with an embodiment of the present invention. The electric annealer 110 is used to anneal the formed glass. In this example, the electric annealer 110 is mounted on a support unit 502 and is supplied electricity from an electrical control box 504. The electric annealer 110 includes a body 506 with an opening 508 formed therein which has a door system 510 attached thereto which when opened provides access to the interior of the body 506 and when closed prevents access to the interior of the body 506. The door system 510 includes a door 512, a frame 514, a gasket 516 and a keeper 518, where the door 512 is attached to the frame 514 which is attached to the gasket 516 which is attached to the keeper 518 which is attached to the body 506 (see FIG. 5C). The configuration of the door system 510 is desirable since the gasket 516 (e.g., tadpole silica gasket 516) is kept cool and has minimal exposure to abrasion because it is positioned between the frame 514 and the keeper 518. In addition, the electric annealer 110 has one or more electrical heating elements 520 located in the body 506 which radiate heat to anneal the formed glass.

As shown in FIGS. 5B and 5D-5G, the electric annealer 110 also incorporates specially designed insulation packages 522 a, 522 b, 522 c and 522 d. In FIG. 5D, the electric annealer 110 has an annealer wall 524 which is made from an outer panel 526 and the specially designed insulation package 522 a. In this example, the specially designed insulation package 522 a includes a ceramic fiber layer 528 (e.g., 1″ thick HP fiber frax 528) located next to the outer panel 526, and a fire brick 530 (approximately 2½″ thick) located next to the ceramic fiber layer 528. The fire brick 530 has an outer face 532 which is exposed to the heat.

In FIG. 5E, the electric annealer 110 has a floor 534 which is made from an outer panel 536 and the specially designed insulation package 522 b. In this example, the specially designed insulation package 522 b includes a fiberglass silicate layer 538 (e.g., 2″ thick insblock 19 538) located next to the outer panel 536, and a fire brick 540 (approximately 2½″ thick) located next to the fiberglass silicate layer 538. The fire brick 540 has an outer face 542 which is exposed to the heat.

In FIG. 5F, the electric annealer 110 has a ceiling 544 which is made from an outer panel 546 and the specially designed insulation package 522 c. In this example, the specially designed insulation package 522 c includes a microporus panel 548 (approximately ½″ thick) located next to the outer panel 546, a ceramic fiber layer 550 (e.g., 2″ thick HP fiber frax 550) located next to the microporus panel 548, and a thermal ceramic layer 552 (e.g., 2″ thick M board 552) located next to the ceramic fiber layer 550. The thermal ceramic layer 552 has an outer face 554 which is exposed to the heat.

In FIG. 5G, the electric annealer 110 has the door 512 which is made from an outer panel 556 and the specially designed insulation package 522 d. In this example, the specially designed insulation package 522 d includes a microporus panel 558 (approximately ½″ thick) located next to the outer panel 556, a ceramic fiber layer 560 (e.g., 2″ thick HP fiber frax 560) located next to the microporus panel 558, and an thermal ceramic layer 562 (e.g., 2″ thick M board 562) located next to the ceramic fiber layer 560. The thermal ceramic layer 562 has an outer face 564 which is exposed to the heat.

Referring to FIGS. 6A-6D, there are several diagrams illustrating in greater detail the exemplary electric crucible kiln 112 in accordance with an embodiment of the present invention. The electric crucible kiln 112 is located below the electric annealer 110 and is used to melt small quantities of glass and colored frits, usually less than 50 lbs. In this example, the electric crucible kiln 112 includes a crucible 602, a door system 604 and an electrical control box 606 which supplies electricity to heating elements (not shown) located in the crucible 602. The door system 604 includes a door 608 which is attached to a support arm 610 which has a hinge 612 connected to the crucible 602. The support arm 610 is arranged to rotate on the hinge 612 such that the door 608 can be moved to cover an opening in the crucible 602 or the door 608 can be moved away from the opening in the crucible 602. Alternatively, the door system 604 if desired may be mounted on a side of the crucible 602 rather than on top of the crucible 602 (as shown).

As shown in FIGS. 6B-6D, the crucible 602 also incorporates specially designed insulation packages 614 a, 614 b, and 614 c. In FIG. 6B, the crucible 602 has walls 616 which are made from an outer panel 618 and the specially designed insulation package 614 a. In this example, the specially designed insulation package 614 a includes a microporus panel 620 (approximately 1″ thick) located next to the outer panel 618, a ceramic fiber layer 622 (e.g., 1½″ thick HP fiber frax 622) located next to the microporus panel 620, a fire brick 624 (approximately 2½″ thick) located next the ceramic fiber layer 622. The fire brick 624 has an outer face 626 which is exposed to the heat.

In FIG. 6C, the crucible 602 has a ceiling 628 which is made from an outer panel 630 and the specially designed insulation package 614 b. In this example, the specially designed insulation package 614 b includes a microporus panel 632 (approximately 1″ thick) located next to the outer panel 630, a ceramic fiber layer 634 (e.g., 1½″ thick HP fiber frax 634) located next to the microporus panel 632, a fire brick 636 (approximately 2½″ thick) located next the ceramic fiber layer 634. The fire brick 636 has an outer face 637 which is exposed to the heat.

In FIG. 6D, the crucible 602 has a floor 638 which is made from an outer panel 640 and the specially designed insulation package 614 c. In this example, the specially designed insulation package 614 c includes a microporus panel 642 (approximately 1½″ thick) located next to the outer panel 640, a fire brick 644 (approximately 2½″ thick) located next the microporus panel 642, a fiberglass silicate layer 646 (e.g., 1½″ thick insblock 19 646) located next to the fire brick 644. The fiberglass silicate layer 646 has an outer face 648 which is exposed to the heat.

Although one embodiment of the present invention has been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it should be understood that the invention is not limited to the disclosed embodiment, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims. 

The invention claimed is:
 1. An electric furnace for processing glass, comprising: a crucible unit; an electrical control box; and a heating unit, coupled to the crucible unit and the electrical control box, wherein the heating unit has an opening formed therein and a door attached to a cantilevered arm which has a hinge connected to at least an outer portion of the heating unit, wherein the cantilevered arm rotates on the hinge such that the door is moved to cover the opening and prevent access to an interior of the heating unit and the crucible unit or the door is moved away from the opening to allow access to the interior of the heating unit and the crucible unit; wherein the crucible unit further comprises: a floor which comprises a first outer panel and a first insulation package, wherein the first insulation package comprises a first microporus panel located next to the first outer panel, a first fire brick located next to the first microporus panel, a first cement castable layer located next to the first fire brick, and a first crucible material located next to the first cement castable layer; a wall which comprises a second outer panel and a second insulation package, wherein the second insulation package comprises a second microporus panel located next to the second outer panel, a first ceramic fiber layer located next to the second microporus panel, a second fire brick located next to the first ceramic fiber layer, a second cement castable layer located next to the second fire brick, and a second crucible material located next to the second cement castable layer; and wherein the heating unit further comprises: a furnace crown wall which comprises a third outer panel and a third insulation package, wherein the third insulation package comprises a third microporus panel located next to the third outer panel, a second ceramic fiber layer located next to the third microporus panel, and a third cement castable layer located next to the second ceramic fiber layer.
 2. The electric furnace of claim 1, wherein the crucible unit is located below the heating unit.
 3. The electric furnace of claim 1, wherein the crucible unit is located under the heating unit, and wherein the crucible unit and the heating unit are coupled to one another such that the crucible unit when needed is able to be decoupled from the heating unit so the crucible unit is able to be moved away from the heating unit.
 4. The electric furnace of claim 1, wherein said heating unit further comprises at least one heating element and a crown suspension system, wherein the crown suspension system comprises a ring of locking bricks and a crown casting, wherein the ring of locking bricks are configured to support the crown casting, and wherein the crown casting is configured to support the at least one heating element.
 5. An electric furnace for processing glass, comprising: a crucible unit; an electrical control box; and a heating unit, coupled to the crucible unit and the electrical control box, wherein said heating unit further comprises at least one heating element and a crown suspension system, wherein the crown suspension system comprises a cast tube forming an outer body of the heating unit which has a rabbit on a bottom edge thereof, where the rabbit is configured to receive a ring of locking bricks which are arranged between the cast tube and a crown casting, where the crown casting supports a crown which in turn supports the at least one heating element, where the ring of locking bricks support the crown casting to prevent the crown from falling down, and the ring of locking bricks also transfer a weight of the crown casting to a lower outside ring on the heating unit.
 6. The electric furnace of claim 5, wherein the crucible unit is located below the heating unit.
 7. The electric furnace of claim 5, wherein the crucible unit is located under the heating unit, and wherein the crucible unit and the heating unit are coupled to one another such that the crucible unit when needed is able to be decoupled from the heating unit so the crucible unit is able to be moved away from the heating unit.
 8. The electric furnace of claim 5, wherein the heating unit has an opening formed therein and a door attached to a cantilevered arm which has a hinge connected to at least an outer portion of the heating unit, wherein the cantilevered arm rotates on the hinge such that the door is moved to cover the opening and prevent access to an interior of the heating unit and the crucible unit or the door is moved away from the opening to allow access to the interior of the heating unit and the crucible unit.
 9. The electric furnace of claim 5, wherein the crucible unit further comprises: a floor which comprises a first outer panel and a first insulation package, wherein the first insulation package comprises a first microporus panel located next to the first outer panel, a first fire brick located next to the first microporus panel, a first cement castable layer located next to the first fire brick, and a first crucible material located next to the first cement castable layer; a wall which comprises a second outer panel and a second insulation package, wherein the second insulation package comprises a second microporus panel located next to the second outer panel, a first ceramic fiber layer located next to the second microporus panel, a second fire brick located next to the first ceramic fiber layer, a second cement castable layer located next to the second fire brick, and a second crucible material located next to the second cement castable layer; and the heating unit further comprises: a furnace crown wall which comprises a third outer panel and a third insulation package, wherein the third insulation package comprises a third microporus panel located next to the third outer panel, a second ceramic fiber layer located next to the third microporus panel, and a third cement castable layer located next to the second ceramic fiber layer.
 10. An electric furnace for processing glass, comprising: a crucible unit; an electrical control box; and a heating unit, coupled to the crucible unit and the electrical control box, wherein the heating unit further comprises a furnace crown wall which comprises a first outer panel and a first insulation package, wherein the first insulation package comprises a first microporus panel located next to the first outer panel, a first ceramic fiber layer located next to the first microporus panel, and a first cement castable layer located next to the first ceramic fiber layer; and wherein the crucible unit further comprises: a floor which comprises a second outer panel and a second insulation package, wherein the second insulation package comprises a second microporus panel located next to the second outer panel, a first fire brick located next to the second microporus panel, a second cement castable layer located next to the first fire brick, and a first crucible material located next to the second cement castable layer; and a wall which comprises a third outer panel and a third insulation package, wherein the third insulation package comprises a third microporus panel located next to the third outer panel, a second ceramic fiber layer located next to the third microporus panel, a second fire brick located next to the second ceramic fiber layer, a third cement castable layer located next to the second fire brick, and a second crucible material located next to the third cement castable layer.
 11. The electric furnace of claim 10, wherein the crucible unit is located below the heating unit.
 12. The electric furnace of claim 10, wherein the crucible unit is located under the heating unit, and wherein the crucible unit and the heating unit are coupled to one another such that the crucible unit when needed can be decoupled from the heating unit so the crucible unit is able to be moved away from the heating unit.
 13. The electric furnace of claim 10, wherein said heating unit further comprises at least one heating element and a crown suspension system, wherein the crown suspension system comprises a ring of locking bricks and a crown casting, wherein the ring of locking bricks are configured to support the crown casting, and wherein the crown casting is configured to support the at least one heating element.
 14. The electric furnace of claim 10, wherein the heating unit has an opening formed therein and a door attached to a cantilevered arm which has a hinge connected to at least an outer portion of the heating unit, wherein the cantilevered arm rotates on the hinge such that the door is moved to cover the opening and prevent access to an interior of the heating unit and the crucible unit or the door is moved away from the opening to allow access to the interior of the heating unit and the crucible unit. 